This invention is directed to organic electroluminescent (EL) devices, and more specifically, to energy-efficient organic EL devices with enhanced operational stability and improved performance characteristics. The organic EL devices of the present invention enable in embodiments high luminescence, excellent stability, and extended lifetimes, and these EL devices can be selected for use in flat-panel emissive display technologies, including TV screens, computer screens, and the like, and as image bar components for digital copiers and printers. More specifically, the present invention relates to organic EL devices with improved charge injection characteristics, low operation voltages, and which devices are, for example, capable of emitting light with uniform and sufficient luminance, and which devices utilize certain novel metal chelate compounds (I) as electron transporting and electron injecting molecules, or wherein the chelates comprise a zone of the EL device, that is for example a luminescent zone, and wherein the chelates are of the formula EQU L.sub.n --M.sup.+n (I)
wherein M represents a metal, n is a number of from 1 to 3, and L is a ligand as represented by Formula (II) ##STR2## wherein Ar is a suitable aryl, or aryl group sufficient, for example, to complete the formula, and wherein aryl contains, for example, about 6 to about 30 carbon atoms, and aryl includes an aromatic heterocyclic group; X is an atom selected from the group consisting of oxygen, sulfur, and selenium; N is nitrogen; O is oxygen; and Z is an aromatic or aryl component, such as 1,2-phenylene, 1,2-naphthylene, 2,3-naphthylene, 3,4-pyridinediyl, 3,4-quinolinediyl, and the substituted analogs thereof with the substituents being preferably selected from the group consisting of alkyl groups with, for example, 1 to about 5 carbon atoms, phenyl, aryl groups with a substituent of a halogen atom or alkyl, and alkoxy with, for example, 1 to 5 carbons; halogen, a carboxy group, a cyano group, and the like.